Controlling dopant solubility in semiconductor alloys

We consider the formation energies and stabilities of dopants in semiconductor alloys. We show that they are not bounded by the formation energies in the related pure materials. On the contrary, by tuning the alloy composition, dopant solubility can be increased significantly above that in the pure materials. Furthermore, it is not always necessary to carry out full defect calculations in alloy supercells, since good estimates of the formation energies at the most stable substitution sites can be obtained by calculating the formation energies in the various component pure materials, but strained to the lattice parameter of the alloy.